Generally, window cases for installing window are mainly made of wood, metal or plastic. The use of window cases made of plastic such as PVC is becoming increasingly common because of advantages of being light and inexpensive.
FIG. 5 is a perspective view showing a joint of a typical window frame.
To manufacture a typical plastic window case, as shown in FIG. 5, a joint 3 at Which window frames 1 intersect at right angles is formed by bringing corresponding portions of the window frames 1 into contact with a heating plate and bonding the melted portions with each other.
As shown in FIG. 5, such a fusion bonding method causes burrs B around the joint 3, particularly, on inner surfaces of the window frames 1, because pressure is applied to the joined window frames 1 during the fusion bonding process.
The burrs generated on the joint 3 must be removed because they act as obstacles when fitting a glass plate into the window frames and defile the appearance of the window case.
Formerly, a worker has used a cutting tool such as a cutter and scraped burrs B to remove them before the burrs B generated on the inner surfaces of the window frames are cooled and hardened. However, such a manual burr removal method has problems in that the worker can easily get hurt and the work productivity in manufacturing the window case is markedly reduced because of long time it takes to manufacture the window case.
A representative example of a conventional deburring device was proposed in Korean Patent Registration No. 10-1092374 (date: May 23, 2011). The conventional deburring device includes: a moving body provided so as to be capable of moving back and forth and having a pair of supports on a front end thereof a scraper rotatably coupled to the supports and provided with a blade extending from the body downward at a predetermined angle; a first elastic member connected at a first end thereof to the scraper and connected at a second end thereof to the moving body so as to elastically support the scraper in one direction; and a locking unit fixing the scraper at a desired work position at which the edge of the blade of the scraper is brought into contact with the surfaces of window frames by rotating the scraper. The scraper removes buns from the inner sidewalls of the window frames while the position of the scraper is converted to the work position by bringing the edge of the blade into the inner sidewalls of the window frames and moving the moving body forward. The scraper also removes buns from the bottom of the window frames when the moving body is moved backward.
However, in the conventional deburring device, to remove burrs generated on inner and outer surfaces of the joint between the window frames, an inner surface deburring operation must be primarily conducted and then a secondary deburring operation must be conducted after the window frames are turned upside down to change the location of the joint of the window frames. Therefore, time required to conduct the deburring operation is excessively increased. Thereby, work productivity is reduced. During the deburring operation, the possibility of a worker getting hurt is comparatively high. It is difficult to simultaneously remove buns generated on inner and outer sides of the joint.